Preparation and treatment of stencil-paper.



ITED STATES PATENT onnion.

DAVID GESTETNER, or TOT'TENHAM HALE, ENGLAND.

PREPARATION AND TREATMENT" OF STENCIL-PAPER.

9'0 Drawing.

To all whom it mag concern:

Be it known that 1, DAVID GnsTETNER, a subject of the King of Great Britain, residing at Tottenham Hale, in the county of Middlesex, England,-haveinvented new and useful Improvements in-the Preparation 'tioned waxes and oil or and Treatment of Stencil-Paper, of which the following is a specification.

This invention relates to improvements in the preparation and treatment of stencil paper with a view to the waxy composition used in its preparation being maintained in a soft condition until the stencil is written and then becoming. hard or dry and tough in a short time to enable it to resistthe action of the inkand the mechanical action of the printiug'process. For this purpose I employ in the preparation of stencil paper a waxy composition consisting preferably of Java paraffin wax or carnauba' wax or amixture of the two in combination with linseed oil or with the fatty acids of linseed oil. Instead, however, of usin the above menatty acids, other waxes, drying oil or fatty acids of a dryingoil may be employed.

The materials may be combined in the followingproportions which I have found to answer well, but other widely different proportions may be used with more or less satisfactory result.

- By weight. Paraffin wax preferably of the Java variety 3parts.

Fine quality of carnau-ba \vax 1 part.

Linseed or other drying oil or a fatty acid of a drying oil 3 parts.

In order that the wax employed may resist attack from the oily ink generally used in printing from stencils, it should be of high quality quite free from the Wax oils and soft waxes. When using carnauba wax it should be of the fatty variety freed from earthy matter and other impurities. Then using linseed oil acids, they are prepared;

preferably from tanked oil that has been well matured and that is quite free from added impurities. This oil should be-treated with caustic soda in quantity insufiicient to completely saponify it. The soapy matter thus formed is broken up with dilute mineral acids. The fatty acids thus liberated are washedfree from mineral acids and glycerin, thus producing linseed oil acids of Specification of Letters latent.

' Patented Jan. 1 9, 11915..

- Application filed November 9, 1908'. Serial No. 461,801.

tainer and preferably in the form of a roll, i

which container then has the air exhausted as far as possible fromlit and is provided with a cover held in close contact with its seat by atmospheric pressure.

It is preferable to place a few drops of turpentine or other volatile material inside the container, which, when the latter is exhausted will give off a vapor which prevents or delays the hardening of the waxy composition. The container-may, however, after exhaustion, be filled with an inert gas.

'The ink employed for use with stencils prepared'as above should not contain any ingredient prejudicial to the waxy composition, such for instance as glycerin, a drying oil or mineral oils. p

Stencil paper having a waxy composition of the character above described spread thereon has the following properties :The waxy composition is soft and easily removed from the paper'by the act of writing a stencil and it can be kept in soft condition for considerable periods when inclosed in a case from which the air is exhausted and which may contain vapor of volatile material or an inert gas. On removal of the stencil paper from its container and on exposure to the. air the waxy composition hardens quickly and the hardening is not appreciably delayed by contact with ink if the latter is of suitablecharacter as above explained nor is it affected by continuous contact with such ink under any climatic condition. J 1

What I claim is I 1. A stencil-paper coated with a composltion comprising pure paraffin wax, and linseed oilin proper proportion to'be and remain soft when air is excluded theresure to air to permit characters to be formed therein by pressing type against the same, and to harden and become dry and tough from, and for a suflicient time afterexpowith comparative rapidity upon exposure to the air, substantially as set forth.

2. A stencil-paper coated with a composition' consisting of soft parafiin wax, car-.

nauba Wax and a rapidly oxidizing material, substantially as set forth.

3. A stencil-paper coated with a compo-, sition comprising a wax-like material and a rapidly oxidizing material, said compo-' 'sition being characterized by the properties of remaining soft when air is excluded therefrom and for a suliicient time after exposure to air to. permit characters to be formed thereon by pressing smooth-faced {type against the same, of being non-adhesive, and of s'eq'uently hardens on exposure to air, such composition comprising a wax-like material and an oxidizing material, forming characters thereon before said coating has hardened, and then permitting the same to harden by sufiicient exposure to the air,'substantially as set forth.

5. The process of manufacturing a stencil, which comprises providing a fibrous base with a coating composition which remains soft out of the presence of air and for a short time after exposure to air, and subsequently hardens on exposure to-air, such composition comprising a wax-like material and an oxidizing material, keeping the stencil out of the presence of atmospheric air from the time said soft coating is applied to the base until occasion for forming characters thereon has substantiallyarrived, then forming characters on said coating, by pressing type or the like against the same, before said coating has hardened, and then permitting said coating to harden by sufiicient exposure to the air, substantially as set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

DAVID GESTETNER.

Witnesses HENRY HAsrnn, WoLDEMAR HAUPT. 

